1. Field of the Invention
The present invention relates to a method of controlling a pressure application resistant welding machine capable of avoiding danger in case that a foreign matter such as fingers is inserted between an electrode and a workpiece when a movable arm of a welding gun such as a stud-gun, a C-type welding gun or an X-type welding gun reciprocates or performs a stroke for applying pressure (hereinafter referred to as a pressure application stroke) to the workpiece.
2. Prior Art
Attempts have been conventionally made to stop the driving of an electric motor by providing a sensor disposed at the periphery of an electrode for detecting a foreign matter which is present between the electrode and a workpiece during welding operation.
If the sensor is disposed at the periphery of the electrode, there arises a problem that the conventional system becomes complex and is deteriorated in workability because of troubles and restriction of use thereof, thereby substantially not performing the welding operation.